The present invention relates to depth finding apparatus and particularly to depth finding apparatus conveniently usable in almost any boat or vessel.
Most depth sounding devices comprise fairly cumbersome apparatus permanently mounted in a vessel, for example including a transducer mounted on the hull of the vessel below the waterline for transmitting sonic pulses under water and receiving echoes therefrom. Echo indicating means are positioned remotely from the transducer at a convenient location for viewing, and the apparatus may be empowered by the power source in the vessel. Although some smaller depth sounding devices are available, they also tend to be multi-unit devices employing moving parts, for example rotatable scanners, and are somewhat unreliable in their operation.
The depth measuring direction for most depth finders is downward, i.e. toward the bottom of the body of water, whereby the device is employed almost entirely to detect the depth of water underneath the vessel. While floating objects or fish may be incidentally detected, there is generally no flexibility or control in the direction of the sonic beam emitted from the usual depth finding device so as to facilitate exploration of a particular underwater area.
Furthermore, prior depth finding devices of the digital output variety have been characterized by a continuously changing and largely erroneous numerical output. The proper output value must be viewed amid false information and is picked out because of the repetition of its presentation, or because of the logical magnitude represented thereby.